RT Journal Article SR Electronic T1 Active surveillance: an essential tool in safeguarding the health and well-being of children and youth JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 169 OP 171 DO 10.1503/cmaj.070775 VO 177 IS 2 A1 Grenier, Danielle YR 2007 UL http://www.cmaj.ca/content/177/2/169.abstract